diff --git a/library/entropy_poll.c b/library/entropy_poll.c
index 67900c46c8..cefe882d2a 100644
--- a/library/entropy_poll.c
+++ b/library/entropy_poll.c
@@ -54,28 +54,43 @@
 #define _WIN32_WINNT 0x0400
 #endif
 #include <windows.h>
-#include <wincrypt.h>
+#include <bcrypt.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1600
+/* Visual Studio 2010 and earlier issue a warning when both <stdint.h> and
+ * <intsafe.h> are included, as they redefine a number of <TYPE>_MAX constants.
+ * These constants are guaranteed to be the same, though, so we suppress the
+ * warning when including intsafe.h.
+ */
+#pragma warning( push )
+#pragma warning( disable : 4005 )
+#endif
+#include <intsafe.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1600
+#pragma warning( pop )
+#endif
 
 int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
                            size_t *olen )
 {
-    HCRYPTPROV provider;
+    ULONG len_as_ulong = 0;
     ((void) data);
     *olen = 0;
 
-    if( CryptAcquireContext( &provider, NULL, NULL,
-                              PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
+    /*
+     * BCryptGenRandom takes ULONG for size, which is smaller than size_t on
+     * 64-bit Windows platforms. Ensure len's value can be safely converted into
+     * a ULONG.
+     */
+    if ( FAILED( SizeTToULong( len, &len_as_ulong ) ) )
     {
         return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
     }
 
-    if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE )
+    if ( !BCRYPT_SUCCESS( BCryptGenRandom( NULL, output, len_as_ulong, BCRYPT_USE_SYSTEM_PREFERRED_RNG ) ) )
     {
-        CryptReleaseContext( provider, 0 );
         return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
     }
 
-    CryptReleaseContext( provider, 0 );
     *olen = len;
 
     return( 0 );
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 290c1eb3d1..3cf1743821 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -65,6 +65,19 @@
 
 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
 #include <windows.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1600
+/* Visual Studio 2010 and earlier issue a warning when both <stdint.h> and
+ * <intsafe.h> are included, as they redefine a number of <TYPE>_MAX constants.
+ * These constants are guaranteed to be the same, though, so we suppress the
+ * warning when including intsafe.h.
+ */
+#pragma warning( push )
+#pragma warning( disable : 4005 )
+#endif
+#include <intsafe.h>
+#if defined(_MSC_VER) && _MSC_VER <= 1600
+#pragma warning( pop )
+#endif
 #else
 #include <time.h>
 #endif
@@ -1126,6 +1139,7 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
     char filename[MAX_PATH];
     char *p;
     size_t len = strlen( path );
+    int length_as_int = 0;
 
     WIN32_FIND_DATAW file_data;
     HANDLE hFind;
@@ -1140,7 +1154,18 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
     p = filename + len;
     filename[len++] = '*';
 
-    w_ret = MultiByteToWideChar( CP_ACP, 0, filename, (int)len, szDir,
+    if ( FAILED ( SizeTToInt( len, &length_as_int ) ) )
+        return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
+
+    /*
+     * Note this function uses the code page CP_ACP, and assumes the incoming
+     * string is encoded in ANSI, before translating it into Unicode. If the
+     * incoming string were changed to be UTF-8, then the length check needs to
+     * change to check the number of characters, not the number of bytes, in the
+     * incoming string are less than MAX_PATH to avoid a buffer overrun with
+     * MultiByteToWideChar().
+     */
+    w_ret = MultiByteToWideChar( CP_ACP, 0, filename, length_as_int, szDir,
                                  MAX_PATH - 3 );
     if( w_ret == 0 )
         return( MBEDTLS_ERR_X509_BAD_INPUT_DATA );
@@ -1157,8 +1182,11 @@ int mbedtls_x509_crt_parse_path( mbedtls_x509_crt *chain, const char *path )
         if( file_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY )
             continue;
 
+        if ( FAILED( SizeTToInt( wcslen( file_data.cFileName ), &length_as_int ) ) )
+            return( MBEDTLS_ERR_X509_FILE_IO_ERROR );
+
         w_ret = WideCharToMultiByte( CP_ACP, 0, file_data.cFileName,
-                                     lstrlenW( file_data.cFileName ),
+                                     length_as_int,
                                      p, (int) len - 1,
                                      NULL, NULL );
         if( w_ret == 0 )
